The purpose of this lesson is to model the effects of reducing or eliminating species in marine ecosystems. It requires student to apply previously learned concepts and terms such as biotic factors, abiotic factors, food web, trophic levels, ecosystem, and biodiversity. Students will also be asked to make predictions as to what affect various fishing strategies has on ecosystems.
Objectives
Students will be able to…
Draw conclusions about the affects of over-fishing on fish populations over time
Predict what will happen to the surrounding ecosystem of over-fished areas
Explain how fishing affects marine ecosystems
Preparation Notes:
Students will work in predetermined groups to avoid loss of instructional time and avoid bickering.
Have all materials counted out and ready before the beginning of class
Let students know they are not to eat the goldfish until the end of class!
We have been discussing the many ways in which humans impact biodiversity and ecosystems. An important way we affect ecosystems is by overusing our natural resources.
How many of you have heard the old saying. “There are plenty of fish in the sea?”
Do you think that is true in a literal sense?
Today we are going to explore the effects of over fishing on fish populations and biodiversity. We will also discuss the affects that fishing gear may have on the ecosystem. Fishing causes major problems to ecosystems and it is something that is happening right now. By the end of today, you will have a better understanding of how fishing impacts biodiversity, fish populations, and the surrounding ecosystem.
Activity
Explain the game rules:
Divide the class into groups of three or four students and have each group choose an ocean name such as North Atlantic, North Pacific, Arctic, Mediterranean, et cetera.
Each student will be a fisher whose livelihood depends on catching fish.
Regular sized Goldfish crackers represent the largest and most valuable fish (tuna, swordfish, et cetera).
Baby Goldfish crackers represent the next most-valuable fish (cod, salmon, et cetera).
Each fisher must catch at least two fish (large or small) in each round to survive (i.e., get enough fish to either eat or sell).
When the fishing begins, students must hold their hands behind their backs and use the fishing rod (straw) to suck fish (Goldfish crackers) from the ocean (bowl) and deposit them into their boat (cup).
The fish remaining in the ocean after each fishing season represent the breeding population, and thus one new fish will be added for every fish left in the ocean (bowl).
Give each group one serving bowl and one cup, and each student one straw, and one copy of the handout Fishing Log.
Put 40 Baby Goldfish crackers and 20 regular Goldfish crackers in each group's bowl.
Say, start fishing and give the students 20 seconds for the first season of fishing.
Have each fisher count his or her catch (Goldfish crackers in their cup) and record the data in their Fishing Log.
Fishers who did not catch the two-fish minimum must sit out for the following round.
Add one new fish for every fish left in the ocean (bowl).
Allow fishers to use their hands on the straws during the second session to represent new technology.
After the second fishing season, give one fisher from each group a spoon representing more new fishing technology such as trawl nets, sonar equipment, et cetera. Continue the game for round three.
Ask, what happened when ocean group [name] ran out of fish? How are the fishers going to survive now? (One option is to move to another ocean.) Allow students to invade other ocean groups when their ocean is depleted, but don't tell them that they can do this beforehand. Fishers may either go as a group to another ocean or they may disperse to other oceans.
Repeat fishing, recording, and replenishing fish stocks until all (or most) groups fish out their ocean.
Have each group make a graph of the changes in their fish populations over time.
Closing
What happened to your fish populations?
Do you think ecosystems can fully recover from over fishing? Why or why not?
Do you think that this model of fishing is accurate? Why or why not?
What do you think we can do to help reduce the affects of fishing on marine ecosystems?
Please finish up your graphs and your worksheets and hand them in by the end of class. If you have not handed in your invasive species outline, please do so now. If you are finished with your worksheet you may work on your invasive species project.
Assessment
Students will be assessed by questions in class and their worksheets
Overview
The purpose of this lesson is to model the effects of reducing or eliminating species in marine ecosystems. It requires student to apply previously learned concepts and terms such as biotic factors, abiotic factors, food web, trophic levels, ecosystem, and biodiversity. Students will also be asked to make predictions as to what affect various fishing strategies has on ecosystems.
Objectives
Students will be able to…
Preparation Notes:
Materials
Instruction
Opening
We have been discussing the many ways in which humans impact biodiversity and ecosystems. An important way we affect ecosystems is by overusing our natural resources.
Today we are going to explore the effects of over fishing on fish populations and biodiversity. We will also discuss the affects that fishing gear may have on the ecosystem. Fishing causes major problems to ecosystems and it is something that is happening right now. By the end of today, you will have a better understanding of how fishing impacts biodiversity, fish populations, and the surrounding ecosystem.
Activity
Explain the game rules:
Closing
Please finish up your graphs and your worksheets and hand them in by the end of class. If you have not handed in your invasive species outline, please do so now. If you are finished with your worksheet you may work on your invasive species project.
Assessment
Students will be assessed by questions in class and their worksheets
References
http://www.rjd.miami.edu/learning-tools/high-school/MODULE%204%20Marine%20Issues%20-%20SECTION%202%20Fishing%20and%20Bycatch.pdf
http://www.pbs.org/emptyoceans/educators/activities/docs/Fishing-fishing-log.pdf
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